Shroud retention wafer

ABSTRACT

An insulative shroud retention wafer for an electrical connector allowing for an optimization of pin placements of the electrical connector is provided. In an illustrative embodiment the shroud retention wafer comprises a first ( 66 ), second ( 68 ), third ( 70 ), and fourth ( 72 ) cylindrical members, each having an axial pin receiving aperture ( 86 ) and an axial center line ( 78, 80 ) extending through the pin receiving aperture ( 86 ). Furthermore, the cylindrical members maintain at least one protuberance ( 100 ). In operation, the cylindrical members of the shroud retention wafer couple with pins of the electrical connector to realize an electrical connection. Specifically, the protuberance ( 100 ) causes collapse of the cylinders ( 66,68,70,72 ) allowing for better gripping of pins of the electrical connector. The arrangement of the cylinders ( 66,68,70,72 ) of the shroud retention ( 28 ) wafer maximizes the number of cylindrical members on the wafer allowing for optimization of pin placement.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to electrical connectors and moreparticularly to arrangements for securing pins in electrical connectors.

2. Brief Description of Prior Developments

Typical prior art shrouds have a designed interference with a matingpin. In the application process the shroud is placed on the pin tip and,with some sort of toe and press, is pushed down the pin against the rearside of a back panel.

One of the difficulties associated with such a procedure is knowing ifthe shroud is properly aligned with the pins. That is, knowing if theshroud is misplaced by perhaps one position. Another problem, is thatthe shroud needs to be held on the pin tips while a tool is placedwithin it and it is placed into a press. It is also found that aspressure is applied to the shroud, the pin may have a tendency to bendcausing pin deformations since the load is being placed on a longslender column.

As is disclosed in European Patent Application No. 578 487 A (U.S. Pat.No. 5,552,730), it is known in the art to provide a structure known as alocking plate or retention wafer between the shroud or housing and thecircuit board or back panel. The arms fit in passageways in the base ofthe housing and these passageways include a camming surface for urgingthe gripping arms into contact with the pins. The disadvantage to theabove arrangement described in European Patent Application No. 578 487 Ais that the interacting protuberance and camming surfaces require thegripping arms or cylindrical members to be displaced from each other ata relatively large distance. The present invention aims to amelioratethe shortcomings of the described prior art by providing an electricalconnector having a shroud retention wafer that acts to more easilycooperate with the pins of the electrical connector thereby avoiding thenecessity of having such pins to be displaced from each other by largedistances and protecting against possible pin deformations.

From the foregoing it is appreciated that there exists a need for anelectrical connector to overcome the disadvantages of the prior art. Byhaving an electrical connector with a shroud retention wafer, thecylindrical members or gripping arms of the electrical connector wouldnot be displaced over a large distance from each other.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a shroud retentionwafer which allows easier shroud application than typical shrouds.

It is another object to provide a shroud retention wafer which producesless damage to pins than typical shrouds.

It is also an object of this invention to provide a shroud retentionwafer which provides better retention than typical shrouds.

The insulative shroud retention wafer of this invention includes aplanar base member having a first and a second side. There are alsofirst, second, third and fourth cylindrical members each having an axialpin receiving aperture and an axial center line extending said pinreceiving aperture. These cylindrical members extend from the first sideof the planar base member, and these cylindrical members are positionedin an arrangement such that a first longitudinal center line extendsthrough the axial center line of the first and second cylindricalmembers. A second longitudinal center line extends in parallel spacedretention to the first longitudinal center line through the axial centerlines of the third and fourth cylindrical members. A first transversecenter line extends through the centerlines of the first and thirdcylindrical members. A second traverse center line extends through thecenter line of the second and fourth cylindrical members. A protuberanceis peripherally positioned on the first cylinder at least in part at aposition between the first longitudinal center line and the firsttransverse center line.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described with reference to theaccompanying in which:

FIG. 1 is a top plan view of a preferred embodiment of the shroudretention wafer of the present invention;

FIG. 2 is a side elevational view of the shroud retention wafer shown inFIG. 1;

FIG. 3 is a front elevational view of the shroud retention wafer shownin FIG. 1;

FIG. 4 is a rear view from 4—4 in FIG. 1;

FIG. 5A is a side view of showing the operation of the shroud retentionwafer with cooperating components in accordance with the presentinvention;

FIG. 5 is an enlarged view of circle 5 in FIG. 4;

FIG. 6 is an enlarged view of Area 6 in FIG. 1; and

FIG. 7 is a further enlarged view of Area 7 in FIG. 6

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The shroud retention wafer of the present invention is an improvement onthe insulative plate with integral insulative sleeves that are shownrespectively at numerals 57 and 56, PCT International Application No. WO96/31922 (U.S. Pat. No. 5,967,844) published Oct. 10, 1996. The contentsof this application are herein incorporated in their entirety byreference.

The wafer is composed of a thin molded base with cylindrical member onits top. Although 30 cylindrical members are shown in the disclosedembodiment, different numbers of cylindrical members may be used invarious other situations. The inside coring of the 20 central cores hasan odd shaped hole in it and two areas of added material on two opposingsides of the tower. The outside 5 cores on each end of the wafer are notpertinent to the wafers function. It will be appreciated that while thecores do not serve for pin retention they do serve for insulation andguidance. As pressure is applied to the opposing areas of addedmaterial, hereafter referred to as “protuberances”, the cylindricalmember will start to collapse, since there will preferably beapproximately 8 mils of plastic on the cylindrical portion 90 degreesfrom the protuberances.

This wafer as shown in FIG. 5A is used in conjunction with a die casthousing 505 which has a matching grid of holes similar to the wafer 28.In practice, the wafer 28 is placed by hand into the bottom of thecasting 505 and pushed (as indicated by the set of arrows 520) to aspecified depth. This piece is then supplied to a user as a shroud whichis placed (as indicated by the set of arrows 525) on the rear side of aback panel 515 by hand. The shroud can be placed over the pins 510protruding from the rear side of the back panel 515 and pushed down tothe board of the rear panel until the wafer 28 contacts the board of therear panel. At this point, the casting is not against the back panel. Apiece of tooling is placed inside the casting, the back panel is thensupported, and casting 505 is fully inserted over the wafer 28. Thewafer 28, which was already pushed against the back panel, cannot moveas the casting 505 is pressed over it. This causes the protuberances 98and 100 to be pushed toward the center of the core and the plastic coreitself to press against the pin 510. This action causes the shroud to besecurely fixed to the back panel 515. The present invention in operatingin this manner offers distinct advantages over current retention wafersincluding the ability to affix a retention wafer over pins of acooperating substrate without the need of excessive tooling, the abilityto secure three piece contact, that is a die casting, a wafer, and acooperating board of a back panel without the need of external fixtures,and the ability to secure an insulative shroud retention wafer that doesnot require the gripping elements to be displaced from each other at arelatively large distance.

Referring now to FIGS. 1-7 the insulative shroud is described as shownin FIGS. 1-3, the retention wafer of the present invention includes aplanar base section 10 which has a first upper side 12 and a secondlower side 14. Extending upwardly from the upward side there is a firstlateral row of cylindrical members shown generally at numeral 16 whichis comprised of members 18, 20, 22, 24 and 26. There is also an opposedlateral row of cylindrical members made up of members 30, 32, 34, 36 and38. Interposed between these lateral rows there are four medial rowsshown generally at 40, 42, 44 and 46. The array of cylindrical membersis also defined by a number of transverse rows shown generally atnumerals 48, 50, 52, 54 and 56. Each of the medial rows has a centerline as, for example, center line 58 of medial row 40 and center line 60of medial row 42. Similarily, each of the transverse rows has a centerline as, for example, center line 62 of row 48 and center line 64 of row50. The medial rows include, for example, first cylinder 66 and secondcylinder 68 in medial row 40 and third cylinder 70 and fourth cylinder72 in medial row 42. Each of the cylindrical members in the medial rowhas a axial center line as, for example, first axial center line 74 incylindrical member 66, second axial center line 76 and secondcylindrical member 68, third axial center line 78 in third cylindricalmember 70 and fourth axial center line 80 in fourth cylindrical member74. As shown in FIG. 6, each of the cylindrical members in the lateralrows such as cylindrical member 30 includes a peripheral base 82, acentral body 84 and a central pin receiving aperture 86. While theselateral row pin receiving apertures allow for insulation of the pinsthey do not serve a gripping function. Each of the cylindrical membersin the medial row as, for example, cylindrical member 66 has aperipheral base 88, and a central body 90. Its central pin receivingaperture through which the first axial center line 74 extends includesan elongated slot 92 and lateral recesses 94 and 96 which extend fromthe elongated 92 at a medial position in opposed directions. The lateralrecesses 94 and 96 are triangularly shaped to receive a crosssectionally square pin. A semi-circular shape for these recesses wouldbe used for a round pin. Each of the cylindrical members in the medialrows also includes a pair of opposed protuberances 98 and 100. Theseprotuberances have respectively center lines 102 and 104. Protuberancecenter lines 102 and 104 are radially aligned respectively with theopposed lateral recesses 94 and 96 in the pin receiving aperture. Theprotuberance center lines 102 and 104 are also displaced from the firstlongitudinal center line 58 and the first transverse center line 62 byan angle of 45 degrees. As shown in FIGS. 4 and 5, protuberances 98 and100 also include vertical wall sections 106 and 108 respectively whichoverly the outer periphery of cylindrical member 66. These walls eachcover about 90 degrees of the periphery of the cylindrical member 66.These walls have a arcuate upper sections 110 and 112 respectively whichcurve inwardly toward the cylinder member to form a cam surface. Thewall also has upper edge 114 and 116 respectively which slope laterallyand downwardly toward the base from their center lines. All of thecylindrical members in the medial rows are essentially similar tocylindrical member 66. Further, the protuberances in these rows aresimilarity positioned on the cylindrical members and have the samerelatively positions to the longitudinal and traverse center lines.

The shroud retention wafer described above may be fixed to a headerprior to shipment of that header thus saving considerable time andeffort during the placement of the header on a back panel or circuitboard. It will also be appreciated that the positioning of theprotuberances as described above on the cylindrical members maximizesthe number of cylindrical members available by reducing the amount ofspace between gripping elements (e.g. protuberances) of the wafer thatare used secure the wafer to cooperating substrates (e.g. rear backpanel). In addition, the shroud retention wafer of the present inventionallows for efficient use of space on the wafer and when cooperating withpins of cooperating electrical connectors server to protect against pindeformations by ensuring that sufficient force is provided to sustain anelectrical connection without unduly offering unnecessary forces to pinsof cooperating electrical connectors.

While the present invention has been described in connection with thepreferred embodiments of the various figures, it is to be understoodthat other similar embodiments may be used or modifications andadditions may be made to the described embodiment for performing thesame function of the present invention without deviating therefrom.Therefore, the present invention should not be limited to any singleembodiment, but rather construed in breadth and scope in accordance withthe recitation of the appended claims.

What is claimed is:
 1. An insulative shroud retention wafer comprising:(a) a planar base member having a first and a second side; (b) first,second, third and fourth cylindrical members extending from the firstside of the planar base member and each having an axial pin receivingaperture and an axial center line extending through said pin receivingaperture wherein said cylindrical members are positioned in anarrangement such that a first longitudinal center line extends throughthe axial center line of the first and second cylindrical members and asecond longitudinal center line extends in parallel spaced retention tothe first longitudinal center line through the axial center lines of thethird and fourth cylindrical members and a first transverse center lineextends through the centerlines of the first and third cylindricalmembers and a second traverse center line extends through the centerline of the second and fourth cylindrical members; and (c) aprotuberance peripherally located on the first cylindrical member atleast in part at a position between the first longitudinal center lineand the first transverse center line.
 2. The insulative shroud retentionwafer of claim 1 wherein there is a second circumferential protuberanceon the first cylindrical member and said second protuberance is locatedat a second position at least in part between the first longitudinalcenter line and the first transverse center line.
 3. The insulativeshroud retention wafer of claim 1 wherein the second protuberance iscircumferentially opposed to the first protuberance.
 4. The insulativeshroud retention wafer of claim 3 wherein the first and secondprotuberances each have a protuberance center lines and saidprotuberance enter lines are each displaced from the first longitudinalcenter line and the first transverse center line by about 45 degrees. 5.The insulative shroud retention wafer of claim 4 wherein the axialaperture includes an elongated slot.
 6. The insulative shroud retentionwafer of claim 5 wherein a pair of opposed pin receiving recesses extendfrom the elongated slot in the pin receiving aperture.
 7. The insulativeshroud retention wafer of claim 6 wherein the elongated slot has alongitudinal axis which intersects the first longitudinal center line atan acute angle.
 8. The insulative shroud retention wafer of claim 7wherein the acute angle at which the longitudinal axis of the elongatedslot intersects the first longitudinal center line is about 45 degrees.9. The insulative shroud retention wafer of claim 8 wherein the recessesextending from the longitudinal slot extend generally perpendicularlyfrom the longitudinal center line of the elongated slot.
 10. Theinsulative shroud retention wafer of claim 9 wherein the recesses aretriangularly shaped.
 11. The insulative shroud retention wafer of claim9 wherein the protuberances each comprise a wall which overlies aportion of the cylindrical member.
 12. The insulative shroud retentionwafer of claim 11 wherein the protuberances each peripherally overliesabout a 90 degrees area of the cylindrical member.
 13. The insulativeshroud retention wafer of claim 11 wherein the protuberance center linesare radially aligned with the recesses extending from the longitudinalslot.
 14. The insulative shroud retention wafer of claim 11 wherein thefirst cylindrical member has a height and the protuberances extend overonly a portion of said height.
 15. The insulative shroud retention waferof claim 14 wherein the protuberances each have an upper edge which iscurved arcuately toward the cylindrical member.
 16. The insulativeshroud retention wafer of claim 15 wherein the upper edge of theprotuberances curves laterally toward the planar base member between theprotuberance center line and the first longitudinal center line and thefirst transverse center line.
 17. The insulative shroud retention waferof claim 1 wherein the second cylindrical member has a pair ofprotuberances which are peripherally positioned on said cylindricalmember in opposed relation at positions between the first longitudinalcenter line and the second transverse center line.
 18. The insulativeshroud retention wafer of claim 1 wherein the second cylindrical memberhas a pair of protuberances which are peripherally positioned on saidcylindrical member in opposed relation at positions between the firstlongitudinal center line and the second transverse center line.
 19. Theinsulative shroud retention wafer of claim 1 wherein the secondcylindrical member has a pair of protuberances which are peripherallypositioned on said cylindrical member in opposed relation at positionsbetween the first longitudinal center line and the second transversecenter line.
 20. The insulative shroud retention wafer of claim 1wherein the second cylindrical member has a pair of protuberances whichare peripherally positioned on said cylindrical member in opposedrelation at positions between the first longitudinal center line and thesecond transverse center line.
 21. An insulative shroud retention wafercomprising: (a) a planar base member having a first and a second side;(b) first, second, third and fourth cylindrical members extending fromthe first side of the planar base member and each having an axial pinreceiving aperture and an axial center line extending through said pinreceiving aperture wherein said cylindrical members are positioned in anarrangement such that a first longitudinal center line extends throughthe axial center line of the first and second cylindrical members and asecond longitudinal center line extends in parallel spaced retention tothe first longitudinal center line through the axial center lines of thethird and fourth cylindrical members and a first transverse center lineextends through the centerlines of the first and third cylindricalmembers and a second traverse center line extends through the centerline of the second and fourth cylindrical members; and (c) aprotuberance peripherally located on the first cylindrical member at aposition angularly displaced from the first longitudinal center line.22. An insulative shroud retention wafer comprising: (a) a planar basemember having a first and a second side; (b) first, second, third andfourth cylindrical members extending from the first side of the planarbase member and each having an axial pin receiving aperture and an axialcenter line extending through said pin receiving aperture wherein saidcylindrical members are positioned in an arrangement such that a firstlongitudinal center line extends through the axial center line of thefirst and second cylindrical members and a second longitudinal centerline extends in parallel spaced retention to the first longitudinalcenter line through the axial center lines of the third and fourthcylindrical members and a first transverse center line extends throughthe centerlines of the first and third cylindrical members and a secondtraverse center line extends through the center line of the second andfourth cylindrical members and the pin receiving aperture is a slotextending through the axial center line of the first cylindrical memberhaving a pair of medial opposed recesses perpendicularly extendingtherefrom; and (c) a protuberance peripherally located on the firstcylindrical member at a position radially aligned with the opposedrecesses extending from the slot.
 23. An insulative shroud retentionwafer comprising a planar base member having a plurality of membersextending from said planar base, each member having an axial pinreceiving aperture that accept contact pins from cooperating electricalconnectors, and protuberances located peripherally to said members,wherein the location of the protuberances provide a retention force onsaid electrical connector contact pins by engaging pin housing membersoffered by said cooperating electrical connectors, said retention forceprotecting against deforming of said electrical connector contact pins.